#include <iostream>
using namespace std;

class Point{
private:
    int _ix;
    int _iy;
public:
    Point(int x = 0,int y = 0):_ix(x),_iy(y){}

    void print() const{
        printf("(%d, %d)\n", _ix, _iy);
    }

};

class Point3D: protected Point{
private:
    int _iz; //添加新的数据成员
public:
    Point3D(int x, int y, int z):
    Point(x,y), _iz(z){
        cout << "Point3D(int*3)" << endl;
    }

    void display() const{ //添加新的成员函数
        print();
        cout << _iz << endl;
    }
};

class Point4D:protected Point3D{
public:

};

void test0(){

}


int main() {
    std::cout << "Hello, World!" << std::endl;
    return 0;
}
